001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.activemq.broker.region.cursors;
018
019import java.util.ArrayList;
020import java.util.Collection;
021import java.util.HashMap;
022import java.util.Iterator;
023import java.util.List;
024import java.util.Map;
025
026import org.apache.activemq.broker.region.MessageReference;
027import org.apache.activemq.command.MessageId;
028import org.apache.activemq.management.SizeStatisticImpl;
029
030public class PrioritizedPendingList implements PendingList {
031
032    private static final Integer MAX_PRIORITY = 10;
033    private final OrderedPendingList[] lists = new OrderedPendingList[MAX_PRIORITY];
034    private final Map<MessageId, PendingNode> map = new HashMap<MessageId, PendingNode>();
035    private final SizeStatisticImpl messageSize;
036    private final PendingMessageHelper pendingMessageHelper;
037
038
039    public PrioritizedPendingList() {
040        for (int i = 0; i < MAX_PRIORITY; i++) {
041            this.lists[i] = new OrderedPendingList();
042        }
043        messageSize = new SizeStatisticImpl("messageSize", "The size in bytes of the pending messages");
044        messageSize.setEnabled(true);
045        pendingMessageHelper = new PendingMessageHelper(map, messageSize);
046    }
047
048    @Override
049    public PendingNode addMessageFirst(MessageReference message) {
050        PendingNode node = getList(message).addMessageFirst(message);
051        this.pendingMessageHelper.addToMap(message, node);
052        return node;
053    }
054
055    @Override
056    public PendingNode addMessageLast(MessageReference message) {
057        PendingNode node = getList(message).addMessageLast(message);
058        this.pendingMessageHelper.addToMap(message, node);
059        return node;
060    }
061
062    @Override
063    public void clear() {
064        for (int i = 0; i < MAX_PRIORITY; i++) {
065            this.lists[i].clear();
066        }
067        this.map.clear();
068        this.messageSize.reset();
069    }
070
071    @Override
072    public boolean isEmpty() {
073        return this.map.isEmpty();
074    }
075
076    @Override
077    public Iterator<MessageReference> iterator() {
078        return new PrioritizedPendingListIterator();
079    }
080
081    @Override
082    public PendingNode remove(MessageReference message) {
083        PendingNode node = null;
084        if (message != null) {
085            node = this.pendingMessageHelper.removeFromMap(message);
086            if (node != null) {
087                node.getList().removeNode(node);
088            }
089        }
090        return node;
091    }
092
093    @Override
094    public int size() {
095        return this.map.size();
096    }
097
098    @Override
099    public long messageSize() {
100        return this.messageSize.getTotalSize();
101    }
102
103    @Override
104    public String toString() {
105        return "PrioritizedPendingList(" + System.identityHashCode(this) + ")";
106    }
107
108    protected int getPriority(MessageReference message) {
109        int priority = javax.jms.Message.DEFAULT_PRIORITY;
110        if (message.getMessageId() != null) {
111            priority = Math.max(message.getMessage().getPriority(), 0);
112            priority = Math.min(priority, 9);
113        }
114        return priority;
115    }
116
117    protected OrderedPendingList getList(MessageReference msg) {
118        return lists[getPriority(msg)];
119    }
120
121    private class PrioritizedPendingListIterator implements Iterator<MessageReference> {
122        private int index = 0;
123        private int currentIndex = 0;
124        List<PendingNode> list = new ArrayList<PendingNode>(size());
125
126        PrioritizedPendingListIterator() {
127            for (int i = MAX_PRIORITY - 1; i >= 0; i--) {
128                OrderedPendingList orderedPendingList = lists[i];
129                if (!orderedPendingList.isEmpty()) {
130                    list.addAll(orderedPendingList.getAsList());
131                }
132            }
133        }
134        @Override
135        public boolean hasNext() {
136            return list.size() > index;
137        }
138
139        @Override
140        public MessageReference next() {
141            PendingNode node = list.get(this.index);
142            this.currentIndex = this.index;
143            this.index++;
144            return node.getMessage();
145        }
146
147        @Override
148        public void remove() {
149            PendingNode node = list.get(this.currentIndex);
150            if (node != null) {
151                pendingMessageHelper.removeFromMap(node.getMessage());
152                node.getList().removeNode(node);
153            }
154        }
155    }
156
157    @Override
158    public boolean contains(MessageReference message) {
159        if (message != null) {
160            return this.map.containsKey(message.getMessageId());
161        }
162        return false;
163    }
164
165    @Override
166    public Collection<MessageReference> values() {
167        List<MessageReference> messageReferences = new ArrayList<MessageReference>();
168        for (PendingNode pendingNode : map.values()) {
169            messageReferences.add(pendingNode.getMessage());
170        }
171        return messageReferences;
172    }
173
174    @Override
175    public void addAll(PendingList pendingList) {
176        for(MessageReference messageReference : pendingList) {
177            addMessageLast(messageReference);
178        }
179    }
180
181    @Override
182    public MessageReference get(MessageId messageId) {
183        PendingNode node = map.get(messageId);
184        if (node != null) {
185            return node.getMessage();
186        }
187        return null;
188    }
189
190}